Several types of anchoring bolt devices are known most of which comprise a screw threaded fixing bolt cooperating with an expandable body or plug made of a material such as wood, plastic or the like. When the fixing bolt is screwed into the body, the body expands against the surrounding material such as concrete, rock or metal into which a bore has been predrilled and in which the expandable body has been inserted. With this type of anchoring bolt, the expandable body is deformed when the fixing bolt is screwed thereinto. For this reason, the anchoring bolt device cannot be taken out of the predrilled bore and used again.
Another known anchoring bolt device includes a wedge-shaped expansion body which is placed in the conical portion of a tubular expandable body. The wedge-shaped expansion body is adapted to cause expansion of the expandable body against the surrounding material when driven by a threaded fixing bolt. When the fixing bolt is loosened and screwed out of the expandable body, the body has not been deformed by the bolt but it would be difficult to loosen the wedge-shaped body out of its wedged position and consequently the expandable body cannot be loosened and taken out of the predrilled bore and used again.
Still another known anchoring bolt device available commercially includes one end portion in the form of a cylindrical body having an internal thread and an other end portion in the form of a tubular split body and a cooperating fixing bolt. The fixing bolt is intended to be "drawn into" the tubular body to expand the same.
For all the anchoring devices described above, the expandable body is inserted first into a predrilled bore with the expandable portion first. The last-mentioned configuration does not permit the fixing bolt to be rotated relative to the tubular body. A threaded nut which coacts with the fixing bolt must therefore be used. This makes the anchoring device complicated and expensive even if the cost, to some extent, could be limited by the fact that the anchoring bolt device under certain circumstances can be reused.